Mineral oil composition and improving agent



Patented Apr. 29, that hnrrrh star aerator MINERAL 01L CQWOSK'EEGN AND EIPBOV ING AGENT Darwin E. Badertscher, Woodbnry, N. 5., assignor to socony-vaonnm Oil Company, Incorporated, New York, my a corporation or New York No Drawing. Application M'ay 26, 1939, Serial No. 275,853

12 Claims. (cease-47) improving agent.

More specifically, one phase of this invention contemplates the stabilization of viscous mineral oil fractions against the harmful efiects of oxid'atlon. Another phase of the invention contemplates improvement of the load-carryingcapacity of mineral oil fractions refined for use under extreme pressure conditions. This invention also contemplates novel oil-improving. agents which may be used. with viscous mineral oil fractions under various conditions of use toeffeet ,the improvement or improvementsnoted above.

As is well known to those familiar with the art, substantially all the various fractions obtained from mineral oilsand refined for their various'uses are susceptible to oxidation.. '1fhe susceptibility of an oil fraction to oxidation and the manner in which oxidation manifests itself within the oil varies with the type and degree of refinement to which the oil'has been subjected and with the conditions under which it is used or tested. In other words, the products formed in an" oilfraction as a result of oxidation and thedegree to which they are formed depends upon the extent to which the variousunstable constituents or constituents which may act as oxidation catalysts have been removed by refining operations, and also upon the conditions of use. i

' A- "highly refined" viscous oil, for example,

- hich is one that has been refined by treatment undesirable. The acids are corrosive to metals and thus reduce the useful life of the oils as lubricants or for other purposes in which they come in contact with metals, and the acidic. inaterials are also injurious in textile lubricants and in spray oils.

Moderately refined oils, which are normally oilsthathave been refined by treatment with onlymoderate amounts of sulfuric acid, or

ot er. refining agents, 'tend to form relatively shall amounts of acidic oxidation products as co pared' withflhighly refined oils, but they undetgo material color depreciation and form considerable amounts of sludge. The changes taking' place in these oils are appreciably accelerated by the presence of metal catalysts -such as copper. Sufilcient acid is generally formed to cause some reduction in the dielectric strength of these oils, but the principal objection to them is their tendency to deposit sludge which interferes with heat transfer in transformers and turbines and also causes plugging of oil feed lines in lubricatin'g systems.

Solventrefined" oils in general, which are normally prepared by treatment with selective solvents, such as chlorex, phenol, furfural, etc.,

' resemble the moderatelyreflned acid-treated oils in that their oxidation isaccelerated by the presence of metals such'as copper and further in that it is attended by substantial color depreciation andsludge formation. Acid formation is usually-greater than in the case of moderately acid-refined oils, but considerably with fuming sulfuric acid or other means or less than with highly. refined oils. Both sludge and acid formation lower their value for many purposes, such-as electrical insulation, lubrication. etc. Also solvent-refined oils have found extensive use as lubricants for internal combustion engines because of their high viscosity index, but under the conditions of use encountered; in crankcases such oils develop constituents which are corrosive toward certain metal bear- -ings such as cadmium-silver bearings, etc.,

ing oil in electrical'equipment such as trans w formers or capacitors an increase in acidic bodies tends to lower the dielectric strength. ofthe oil and has other harmfulefiects which are.

which are sometimes used.

It is to beunderstood that this classification of oils as highly refined," moderately refined" and.so1vent-'refinedf is by no means limiting and that there can exist oils whose refining and blending has been such as to make them intermediate in properties between the types set up. 'lhus, response to inhibitors may be said to depend entirely upon the type of oxidation-and end products of oxidation of an oil, which in turn degree of refining. this depends largeL upon the oil has had. Further,

the degee of refining 'ret quired to produce these types of oils varies with the crude source so that any one refining procedure may produce either a highly refined oil or a moderately refined oil, depending upon the crude source. Pennsylvania type oils, for example,. require much less refining to produce highly refined oils than the Coastal type of oils.

The use of oxidation inhibitors for the purpose of stabilizing a viscous mineral oil fraction against the deleterious effects of oxidation discussed above is well known. Since the action of these inhibiting materials is apparently catalytic, the problem of their development is a diflicult one and is evidently influenced to a large degree by the oxidizable constituents which are in the oil following a particular refining treatment. Thus, a particular inhibitor or class of inhibitors may be effective to stabilize a highly refined oil against acid formation while "the same inhibitor may have no appreciable effect upon acid, color or sludge formation in a moderately refined oil and vice versa. The same inhibitor may or may not be efiective in inhibiting acid, sludge and color formation'in a solvent-refined oil and may or may not be eifective to inhibit the corrosive action. of a solvent-refined oil toward metals such, for example, as the various normally corroded alloys typified by cadmiumsilver bearings.

The compounds of the present invention are particularly useful as inhibitors of acid formation in highly refined oils, inhibitors of bearing corrosion in solvent-refined motor oils under conditions of 'crankcase use, and also as extreme.

pressure bases in lubricants of the type used in hypoid gears, etc. The tests which I have conducted indicate that these compounds do not show appreciable effect toward the inhibition of the deleterious effects of oxidation upon moderately refined mineral oil fractions of the turbine oil type..

Although'this invention is broadly concerned with any viscous mineral oil fraction containing an improving agent falling into the class of novel compounds contemplated- ,here'in, it is more specifically concerned with the stabilization of the so-called highly refined oils against acid formation, the stabilization of moderately refined oils against alloy bearing corrosion and the improvement of the load-carrying capacity of lubricating 0118 of the extreme pressure type.

The compounds contemplated herein as oil-im- Drovmg agents are obtained by the reaction of an alkali alkyl xanthate on a beta-chlorethyl amine. The products obtained by such reaction cannot be classified with certainty as definite chemical compounds and are therefore referred to and defined herein merely as products of the reaction generally described above. The general procedure followed in effecting this reaction is to employ substantially equivalent proportions of the alkali alkyl xanthate and the beta-chloroethyl amine, such compounds being admixed with a suitable liquid medium, such as ethyl alcohol, and refluxed for a substantial period of time, during which thecompounds react with the release of an alkali chloride. The alkali chloride is separated from the reaction product in any suitable manner, such as by filtration, and the reaction product is subjected to purification which will be described in greater detail later on.

Although, as indicated above, I do not wish to be bound by any theory'as to what reaction takes place or as to what the chemical composition of the reaction product is, it does appear from the 75 reactants used and the sulfur and nitrogen content of the reaction product that when an alkali alkyl xanthate is reacted with-a tris(beta-chloroethyDamine, the reaction takes place according to the following equation: 3ROCS--SM+ (ClCHzCHz) aN- in which R indicates an alkyl group such as ethyl,

propyl, butyl, amyl, etc., and M indicates an al- 1 pared from potassium butyl xanthate and tris-' (beta-chloi'oethynamine according to the following procedure:

A mixture of 12 grams of tris(beta-chloroethyllamine, 39 grams of potassium butyl xanthate, and 200 cc. of a suitable solvent such as 95 per cent ethyl alcohol was stirred and refluxed for a period of 5 hours. The white solid potassium chloride which had been separated was filtered off and washed with hot alcohol. A yellow lower layer formed in the filtrate and was separated from the alcohol, the alcohol layer being drowned in water and the separated material being extracted twice with benzene and twice with ethyl ether. The original yellow lower layer was combined with the extract and filtered and distilled to remove the solvent. This procedure yielded grams of residue of pale yellow oil which analyzed without further purification 2.77 per cent nitrogen and 35.2 per cent sulfur. 0n the basis of an assumed composition, CnHsaOaSsN, which in the equation above would be per cent and oils.

EXAMPLE I (HIoHLY REFINED OILs) The oil employed in this test was of the highly refined type used in transformers and the like which had been obtained from a Coastal distillate by successive treatments with 98 per .cent sulfuric acid in the ratio of poundsper barrel and 103 per cent oleum in the ratio of 189 pounds per barrel, followed by neutralization, washing, and clay percolation. The refined oil had a specific gravity of 0.871 and a flash point of 310 F. and a Saybolt Universal viscosity of 69 seconds at F. It was tested by heating a.- 150 gram sample of the oil or the oil blend to C. and ebubbling oxygen gas therethrough for a period of 70 hours. The amount of acidic oxidation products thus formed in the oil was determined by titration with standard alkali and the results recorded in terms of neutralization number (N. N.)

which represents the number of milligrams of KOH required to neutralize the acids formed in one gram of oil. The results of this test are set forth in Table I below, in which it will be observed that the reaction product contemplated by this invention was eii'ective to inhibit to a sub stantial degree the acid formation in this highly refined oil.

- the lubrication of hypoid gears and The extreme pressure properties of these reaction I desired to improve.

the range of proportions, taking in both the oxipreviously pointedon 2,240,009 Table! I i Neutralization No. 1. A mineral oil composition comprising a visafter test cous mineral oil 1:- tion having in admixture 011 alone 25.0 therewith a minor roportion oi the reaction Oil+0.10% of tris (beta-chloroethyl) amine and potassium butyl xanthate reaction product 0.29 ELE II (SOLVENT-REFINE!) Moron 01L) The-oil used in this test was an S. A. E. 20 motor oil obtained from a Pennsylvania; mixed neutral residuum stock by solvent-extraction with Chlorex. It had a specific gravity of 0.87, a flash point of 4357 F; and a S. U. viscosity of 818'seconds at 100 F. The test used comprised passing a current of air at the rate of 2000 mls. per hour through a 50 ml. sample of the oil heated toa temperature of 347 F. for a period or 22 hours in the presence of a fi-gram section taken from a. cadmium silver bearing. The weight loss in' milligrams was interpreted as a measure of the corrosiveness of the oil or oil blend and the results of this test using the oil alone andthe same oil containing 0.25 per cent of the reaction product described above are given in Table II below.

Table II Oilalon Oil+0.25% oftris (beta-chloroethyl) amine and potassium butylxanthate reaction product possess the property of improving the load-carrying capacity of lubricants designed for use under extreme pressure conditions as, for example, in

the like.

products was demonstrated by a conventional extreme'pressur test known as the S. A. E. test, in' which the oil alone pounds, whereas an oil blend containing per cent of the reaction product described above passed the test at a load of 580 pounds at 750 R. P. 'M. A

It is to be understood that reaction products of the type contemplated by this inventiomcan be used in the oil in various proportions, depending upon the oil fraction to which. they are Weight loss (mgs) failed at a load of.15'

.vent medium;

product obtained by dissolving substantially equivalent proportions of an alkali alkyl xan'thate' 2. A mineraloil composition comprising a ViS- J.

cous mineral oil fraction having in admixture therewith a minor proportion of the reaction product obtained by dissolving substantially equivalent proportions of potassium butyl xanthate and tris (beta-chloroethyl) amine in a suitable solvent medium; refluxing the mixture'ior a suiflcient period of time to precipitate potassium chloride and form the reaction product; and removing the potassium chloride and the solvent from said reaction product.

3. A mineral oil composition comprising a viscous mineral oil fraction selected from the group consisting of highly refined viscous oils and solvent-refined motor oils having in admixture therewith a. minor proportion of the reaction product obtained by dissolving substantially equivalent proportions of an alkali alkyl xanthate and a beta-chloroethyl amine in a suitable solvent medium; refluxing the mixture for a suflicient period of time to precipitate alkali chloride and form the reaction product; and removing the alkali chloride and the solvent from said reaction product.

4. An extreme pressure lubricant composition comprising a major proportion of mineral lubrieating oil and-a minor proportion oi the reaction product obtained by dissolving substantially equivalent proportions of an alkali alkyl xanthate and a beta-chloroethyl amine in a suitable solrefluxing the mixture. for a sumcient period of time to precipitate alkali chloride and form the reaction product; and removing the alkali chloride and the solvent from said reaction product.

added and the particular properties which it is 1 In. general it appears that dation-inhibitive action and the extreme pressure action, will be from. about 0.05 per cent to about 15 per cell v It is also to be understood that the terms highly refined" and solvent-refined" as used herein are not necessarily restricted to a particular refining treatment but have reference to oils or oil fractions corresponding substantially in their mannerof deterioration and inhibitor response to the examples given. As has been the flnal characteristics of a mineral oil fraction are aiieoted by the crude oil from which such fraction is obtained, as well. as by the refining treatment to which it has been subjected. choice. of a particular crude to obtain a highly refined oil with a refining treatment which when applied to another crude would yield anoil oi the moderately refined type. 1 if It is possible, for example, by thevent-refined motor oils 5. A mineral oil composition comprising a viscous mineral oil fraction selected from the group consisting of highly-refinedviscou; oils and solhaving in admixture therewith a minor proportion of the reaction product obtained 'by dissolving substantially equivalent proportions of potassium butyl xanthate and tris(beta-chloroethyl) amine in a suitable solvent medium; refluxing the mixture for-a sumcient period of time to precipitate potassium chloride and form the reaction prod= not; and removing the potassium chloride the solvent from said reaction product.

6. An extreme pressure lubricant composition comprising a major proportion of mineral lubri cating oil and a minor proportion of the reaction product obtained by dissolving substantially equivalent proportions of potassium butyl xanthate and tris(beta-chloroethyl amine in a suitable solvent medium; refluxing the mixture for a sufllcient period of time to precipitate potassium chloride and form the reaction prodnot; and removing the potassium chloride and the the solvent from the reaction product.

7. A mineral oil composition comprising a viscous mineral oil traction having in admixture therewith a minor proportion oi the reaction product obtained by reacting together under reproportions of an alkali 'alkyl xanthate and about one molecular proportion of tris (betachlorw ethyl) amine for a suflicient period of time to precipitate an alkali chloride and form the reaction product, and-separating the alkali chloride and the solvent from the reaction product.

8. A mineral oil composition comprising a vis cous mineral oil fraction having -in admixture therewith from about 0.05% to about 15% of the reaction product obtained by reacting together under reflux'in a suitable solvent substantially equivalent proportions of an alkali alkyl xanthate and a beta-chloroethyl amine for a suflicient period of time to precipitate an alkali chloride and form the reaction product, and separating the alkali chloride and the solvent from the said reaction product.

9. A mineral oil composition comprising a v'viscous mineral oil fraction having in admixture I therewith from about 0.05% to about 15% of the reaction product obtained by reacting together under reflux in a suitable solvent about three molecular proportions of an alkali alkyl 'xanthate and about one molecular proportion of tris'(betachloroeth-yl) amine for a sufiicient period of time to. precipitate an alkali chloride and form the reaction product, and separating the alkali chloride and the solvent from the reaction product.

o flux in a suitable solvent about three molecular 10. A mineral oil improving agent comprising the product obtained by reacting together under reflux in a suitable solvent substantially equivalent proportions of an alkali alkyl xanthate and a beta-chloroethyl amine for a sufiicient period of time to precipitate alkali-chloride and form the reaction product and separating the alkali chloride and the solvent from the said reaction product. a

11. A mineral oil improving agent comprising the product obtained by reacting together under reflux in a suitable solvent about three molecular proportions of an alkali alkyl xanthate and about one molecular proportion of tris(beta-chloroethyl) amine for a sufiicient period of time to pre cipitate alkali chloride and form the reaction product, and separating the alkali chloride and the solvent from the said reaction product.

12. A mineral oil improving agent comprising the product obtained by reacting together under reflux in a suitable solvent about three molecular proportions of potassium butyl xan'thate and about one molecular proportion of tris(beta- DARWIN E. BADERTSCHER. 

